ixgbe/igb: catch invalid VF settings

Some ixgbe cards put an invalid VF device ID in the PCIe SR-IOV
capability.  The ixgbe driver is only valid for PFs or non SR-IOV
hardware.  It seems that the same problem could occur on igb hardware as
well, so if we discover we are trying to initialize a VF in ixbge_probe
or igb_probe, print an error and exit.

Based on a patch for ixgbe from Chris Wright <chrisw@sous-sol.org>.

Signed-off-by: Andy Gospodarek <andy@greyhouse.net>
Cc: Chris Wright <chrisw@sous-sol.org>
Acked-by: Chris Wright <chrisw@sous-sol.org>
Acked-by: Greg Rose <gregory.v.rose@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>